A known sheet transport device includes a sheet feeding tray, a pick-up roller, a separation roller, a friction pad, and a separation wall.
The sheet feeding tray has an upper surface serving as a support surface for supporting sheets. The pick-up roller faces the support surface. The pick-up roller feeds sheets supported on the support surface downstream in a transport direction along the separation wall. The separation wall has a slope extending obliquely upward downstream in the transport direction toward the separation roller and the friction pad. The separation roller and the friction pad separate multiple sheets fed by the pick-up roller from one another, and transport each separated sheet downstream in the transport direction.